It began with an informal chat over a Coke and a bottle of Appletise

WHEN BBC reporter Andrew Gilligan and his contact, the government scientist Dr David Kelly, met for a drink in the bar of London's Charing Cross Hotel, neither man could have imagined the fateful consequences their talk would have.

WHEN BBC reporter Andrew Gilligan and his contact, the government scientist Dr David Kelly, met for a drink in the bar of London's Charing Cross Hotel, neither man could have imagined the fateful consequences their talk would have.

Even today what exactly was said remains a matter of dispute - with Dr Kelly's family refusing to accept Mr Gilligan's account of their conversation.

What is undoubtable, is that an informal chat over a Coke and a bottle of Appletise turned into an interview that rocked the institutions of government and the BBC, and resulted in Rhondda-born Dr Kelly taking his own life.

In efforts to discover the truth, Mr Gilligan's personal organiser - on which he made the brief notes of their meeting on which he based his account - has been subjected to expert examination for evidence that they had been doctored.

During Dr Kelly's lifetime they could not even agree on when they first met or exactly when their meeting at the Charing Cross Hotel took place.

On that point at least, however, Mr Gilligan's version that it was around 4pm on May 22 appears to be borne out by his bar receipt, which timed the purchase of the two soft drinks at 4.15pm.

Dr Kelly had thought they had met an hour later.

Although it was a relatively minor discrepancy, it was symptomatic of the difficulties that were to emerge in pinning down what transpired that afternoon.

Both men did agree that the ostensible purpose of their getting together was to discuss the recent war in Iraq, which Mr Gilligan had covered for the Radio 4 Today programme from Baghdad.

Dr Kelly, a former United Nations inspector who had helped uncover Saddam's biological weapons programme in the 1990s, was due to return to the country to join the hunt for Iraq's elusive weapons of mass destruction and was keen to pick up information about the situation on the ground.

They also agreed that at some point the conversation turned to the Government's dossier on Iraq's weapons published the previous September, prior to the war. But after that, accounts differ.

It does, however, now seem clear - although he always denied it - that Dr Kelly passed on two crucial pieces of information: that the controversial claim in the dossier that some Iraqi weapons could be deployed within 45 minutes had come from a single source and that the intelligence had come in late.

He also seems to have spoken about unhappiness within the intelligence community about the way the dossier was compiled.

More contentiously, Mr Gilligan said Dr Kelly had told him that the 45 minute point had been included following the intervention of the No 10 director of communications, Alastair Campbell, against the wishes of the agencies.

Mr Gilligan has always maintained that it was Dr Kelly who first mentioned Mr Campbell's name.

Dr Kelly, however, told a colleague that it was the journalist who put Mr Campbell's name to him in a "name game" intended to elicit information.

Although he was not a member of the intelligence services, Dr Kelly was regularly consulted by both MI6 and the Defence Intelligence Staff - the intelligence arm of the Ministry of Defence - about biological and chemical weapons issues, making him an excellent source for Mr Gilligan.

He had also written the section of the dossier covering the history of UN weapons inspections in Iraq following the first Gulf War, and was renowned for his work in uncovering both Iraq's and Russia's biological weapons programmes.

One week later, on May 29 at 6.07am, Mr Gilligan made his first broadcast of the morning for Today - Radio 4's flagship news and current affairs programme.

Speaking from his London flat, in an unscripted, live "two-way" with presenter John Humphrys, he said that the 45 minute claim had been included in the dossier even though the Government knew it was probably "wrong".

He said that in the week before publication Downing Street had ordered it to be "sexed up" and new facts "discovered" to make it more exciting.

He said that the intelligence had, unusually, been single-sourced, and was included against the wishes of the intelligence agencies.

Mr Gilligan described his source for the story as "one of the senior officials in charge of drawing up the dossier".

In his second broadcast, at 7.32am, he toned down the language somewhat - saying the 45 minute claim was "questionable" rather than "wrong". However the gist of the story was much the same.

Mr Campbell, on his way to Iraq with Tony Blair to visit the victorious British forces, was furious.

He saw it as a direct and unwarranted attack on the integrity of the Government and authorised Downing Street to issue a vigorous denial, insisting the dossier was entirely the work of the intelligence agencies.

However the story was given some credence by an admission by Armed Forces Minister Adam Ingram that the 45 minute claim was indeed single sourced.

In the coming days more denials were to follow from Mr Blair himself and from Foreign Secretary Jack Straw.

But although it was stated that John Scarlett, the chairman of the Joint Intelligence Committee - the body responsible for drawing up the dossier - had rejected the claims of political interference, the story would not go away.

Indeed, Mr Gilligan fanned the flames three days later with an article for The Mail on Sunday in which he stated for the first time that his source had named Mr Campbell, saying he was behind the changes to the dossier.

When Parliament returned from its Whitsun break the political storm broke with the Commons Foreign Affairs Committee (FAC) announcing an inquiry into the decision to go to war, with Mr Gilligan among the main witnesses.

On June 25, Mr Campbell - who had initially resisted demands to give evidence - appeared before the FAC and bitterly condemned the BBC story as a "lie" and demanded a retraction from the corporation.

Two days later, with the BBC standing firm despite a barrage of letters from Downing Street, Mr Campbell made an extraordinary, unheralded appearance on the Channel 4 News, to denounce the BBC in even stronger terms.

Suspecting the leak may have come from his department, the Permanent Under Secretary at the MoD Sir Kevin Tebbit had asked the deputy chief of defence intelligence Martin Howard to make inquiries.

Dr Kelly had already come under suspicion over other leaks to the media and has admitted to Foreign Office colleague Patrick Lamb that he had met Mr Gilligan.

Mr Howard summoned Dr Kelly to an interview but, perhaps sensing the net was closing in, Dr Kelly took matters into his own hands and wrote to his line manager at the MoD admitting he had met Mr Gilligan but denying the comments about Mr Campbell or the 45 minute point.

He said that he believed that Mr Gilligan must have had another source or had "embellished" his account of their conversation.

On July 4 he was interviewed by the MoD's director of personnel Richard Hatfield, with his line manager Bryan Wells also present.

Mr Hatfield accepted Dr Kelly's account of his talk with Mr Gilligan but rebuked him for his contacts with journalists which had not been properly cleared with the MoD.

He said that the scientist would notface disciplinary action on this occasion although he was warned as to his future conduct.

Dr Kelly was also told that there may have to be some form of public statement.

And that, as far as those present were concerned, was the end of the matter. However, elsewhere in Whitehall, important people had other ideas.

Defence Secretary Geoff Hoon had passed the news to Downing Street that an official had come forward who could be the BBC's source and the information was relayed to Tony Blair who was on a regional tour of the North West.

Mr Campbell noted in his diary, "It was double-edged but GH (Geoff Hoon) and I agreed it would stuff Gilligan if that was his source".

Over the weekend there was a flurry of communications among senior officials. Mr Blair, by now at his country residence at Chequers, made clear that he believed that Dr Kelly needed to be re-interviewed.

Meanwhile the BBC Board of Governors, unaware of developments in Whitehall, was meeting in emergency session that Sunday to discuss the escalating war of words with the Government.

After receiving assurances from senior managers they issued a bullish statement defending the Today programme's handling of the story and insisting that it had been in the public interest.

The mood was encapsulated in an internal e-mail by Downing Street press spokesman Tom Kelly, who wrote, "This is now a game of chicken with the Beeb - the only way they will shift is (if) they see the screw tightening".

What the governors did not know was that doubts were beginning to surface within the BBC itself.

The editor of Today, Kevin Marsh, admitted to his immediate superior that the story had been "marred by flawed reporting" and "loose use of language" and suggesting that in future Mr Gilligan should be kept on a tighter rein.

At Westminster, however, attention was now focused on the FAC's keenly-awaited report on the Iraq war.

But when Mr Blair met senior officials in Downing Street, they also turned to the question of Dr Kelly.

Although no minutes were taken, it appears it was agreed that he should face a "more forensic examination" of what he said to Mr Gilligan. A "proper security-style interview" in which all the inconsistencies could be "thrashed out" was suggested.

From the outset, it seems, all involved were working on the assumption that Dr Kelly's name would very quickly become public one way or another.

That view was reinforced by an article in The Times which quoted "BBC insiders" as saying that the Today programme's source was a military expert based in Iraq - where Dr Kelly had recently visited.

By now, however, the scientist was in RAF Honnington in Lincolnshire on a training course for weapons experts preparing to return to Iraq.

He was hurriedly summoned back to London for a second grilling.

While Dr Kelly stuck to his story, Mr Howard concluded that he must be the source for Mr Gilligan's story, even if some of the details had been embellished.

In his report, Mr Hatfield said he had warned Dr Kelly that the MoD would have to make some kind of public statement and that it was "quite likely" his name would come out.

They discussed a brief draft statement prepared by the MoD.

The next morning Mr Blair summoned the same group of officials who had met the day before for another meeting.

It was decided that a statement was now inevitable.

After a number of options was considered then rejected, a group of officials trooped into the office of Godric Smith, one of Mr Campbell's two deputies, to begin reworking the early MoD draft.

Later that afternoon Permanent Under Secretary at the MoD Sir Kevin Tebbit returned to the MoD with an agreed wording.

The statement was read to Dr Kelly in a call to his mobile phone shortly after 5pm.

The call lasted less than 4 minutes and Dr Kelly did not raise any objections even though the statement was considerably more detailed than the early draft he had been shown.

By 6pm it had been released to journalists, just in time for the evening news bulletins.

The statement said that "an individual working in the MoD" had come forward to say he had had an "unauthorised meeting" with Mr Gilligan at which they discussed the Iraq dossier.

It also offered the information that the official concerned was an expert on WMD who had advised ministers on the subject and who had written a historical account of the UN inspections in Iraq for the dossier.

That evening Mr Hoon wrote to the chairman of the BBC Board of Governors, Gavyn Davies, offering to name the official in confidence if the BBC would then say whether he was their source.

When Mr Davies refused, Mr Hoon wrote back with Dr Kelly's name - in confidence - but again the BBC chairman refused to bite.

The BBC issued its own statement casting doubt on whether the official who had come forward was its source, saying that the description did not match Mr Gilligan's contact "in a number of important ways".

As well as its press statement, the MoD had also prepared a "defensive briefing" note in the form of a question-and-answer sheet for press officers, to guide them on how to deal with follow-up queries from journalists.

Unbeknown to Dr Kelly the Q&A authorised press officers to confirm his identity if journalists came up with the right name.

The Q&A also contained further details about Dr Kelly which could be released, including the fact that he was a former UN weapons inspector and had recently spent a week in Iraq.

To Dr Kelly's family, it effectively amounted to a deliberate "naming strategy" to lead journalists to his identity.

The following morning Defence Secretary Geoff Hoon was informed of the Q&A material at his daily meeting to discuss media issues.

With journalists pressing for information, the Prime Minister's official spokesman Tom Kelly confirmed the further details.

By now the MoD press office was being bombarded by calls as word went around that it was prepared to confirm the official's identity if journalists came up with the right name.

One reporter trawled the internet for likely candidates while another put 20 names to the press office before coming up with the right one.

By 6pm that evening, it was being officially confirmed that the official was Dr Kelly.

It was, however, another hour before he was told what was happening in a brief phone call.

But it seems that it only sank in half an hour later when Sunday Times journalist Nick Rufford turned up on his doorstep.

He warned Dr Kelly - who had spent the day listlessly tending his vegetable patch at his home in the Oxfordshire village of Southmoor - that the rest of the press were on their way "in droves".

Dr Kelly and his disabled wife Janice quickly packed their bags and left.

The following days were later described by Mrs Kelly as a "nightmare" as they headed down to Cornwall to an address she knew where they could stay.

Her husband, who had become increasingly tense and withdrawn, now seemed to turn completely in on himself.

Mrs Kelly told the Hutton Inquiry that he was "desperately unhappy" and had felt "totally let down and betrayed" by his employers at the MoD who, she said, had given him assurances that his name would not be made public.

She tried to distract him with visits to the Lost Gardens of Heligan and the Eden Project, but he went "ballistic" when he was informed by the MoD that he would have to give evidence the following week at a televised hearing of the Foreign Affairs Committee.

Dr Kelly returned to the MoD to be briefed on any "tricky areas" which he could be questioned on.

One Foreign Office official noted, "Kelly is apparently feeling the pressure and does not appear to be handling it well."

The scientist was clearly deeply uncomfortable when he appeared before the FAC and his voice was barely audible.

He was given a rough ride after he said that he did not believe that he could be Mr Gilligan's source as there were too many discrepancies.

He was described by Labour MP Andrew Mackinlay as "chaff" and a "fall guy" put up by the MoD to divert the committee's attention.

However it seems that what really threw him was a question from Liberal Democrat MP David Chidgey who asked if he was the source of another story on the Iraq dossier on BBC2's Newsnight by science editor Susan Watts.

Although Dr Kelly admitted talking to her he denied that he was her source and appeared taken aback when Mr Chidgey said that he had been told by Ms Watts that he was.

In fact, Mr Chidgey, along with two Tory MPs on the committee, had received an e-mail from Mr Gilligan - who was still refusing to say whether Dr Kelly was his source - saying that the scientist was the source of Ms Watts's story.

However Mr Gilligan did not actually know that Dr Kelly was also Ms Watts's source and had simply been guessing. He later admitted that he had been wrong to do so.

Back home in Southmoor, it may have appeared that the worst was over. Dr Kelly e-mailed several colleagues optimistically expressing his hope that he would soon be back in Iraq to join the WMD hunt.

However the worries came crowding back. Throughout the morning he was receiving calls from the MoD asking for information about his contacts with journalists so that they could respond to written parliamentary questions tabled by MPs.

The final call specifically referred to his contacts with Ms Watts.

Shortly afterwards, having told his wife he was going for a walk, Dr Kelly slipped out of the house with his old Boy Scouts knife and 30 of Mrs Kelly's Co-proxamol tablets, and set off on foot for Harrowdown Hill - a local beauty spot.

That was where a police search team discovered his body at 9.20am the following morning with his left wrist slit and the tablet packets empty.

Later that day a shocked Mr Blair - on a tour of the Far East - announced that there would be a public inquiry into his death.

Two days later the BBC issued a statement confirming that Dr Kelly been the source of both Mr Gilligan's and Ms Watts's reports.

Mr Blair told journalists travelling on his plane that it was "completely untrue" that he had authorised the naming of Dr Kelly.

The following week in Baghdad, away from the glare of publicity, there was a moving gathering of some 30 of Dr Kelly's former colleagues to remember a man they had known and admired.